WASHINGTON — The US Border Patrol recently ordered an investigation into allegations that its agents were mistreating illegal immigrants entering the United States, said Michael Fisher, the agency's chief.

In the Border Patrol, "We do take all those (allegations) very seriously," Fisher said Wednesday at a House of Representatives hearing.

The allegations were made by non-governmental organizations that operate along the US border with Mexico.

"We turned all of those allegations of misconduct over to the office of the inspector general" of the Homeland Security Department, Fisher told the House Appropriations Homeland Security subcommittee.

He also pledged to provide "all the relevant information" to investigators. He was unable to say how many investigations were being conducted.

Representative Lucille Roybal-Allard, a California Democrat, said the allegations might reflect a "series of deeply troubling abuses."

They include charges that Border Patrol agents engaged in violence and sexual abuse of illegal immigrants, unjustly seized their property and denied them food and drink for extended periods of time.

Fisher replied by saying, "I require all Border Patrol agents to comply with and enforce the laws that Congress passes with a degree of consistency and compassion."

He said officials from his office had been discussing the abuse allegations with non-governmental organizations that made the complaints.

Fisher made his comments while defending the Border Patrol's fiscal 2013 draft budget, which the Obama administration proposed at nearly $12 billion.

He said that between 2009 and 2011, the Border Patrol increased its seizures of illegal weapons by 159%, illicit drugs by 41% and cash confiscated from criminal activity by 74% compared with the previous three years.

The Border Patrol operates with about 21,000 agents.